Long-term prospective epidemiologic studies on hypertensive and atherosclerotic cardiovascular diseases, particularly coronary heart disease, are in progress, to elucidate key practical and theoretical questions left unclarified by studies to date. For this purpose, use is being made of data on two cohorts of men employed by the Chicago Peoples Gas Co. and one cohort of men employed by the Western Electric Co., plus data from the national cooperative Pooling Project. The contributions of the following variables to risk of death both cause-specific and all causes, are being assessed by univariate and multivariate procedures; plasma glucose level 1 hour after 50 gram oral load, history of diabetes mellitus, serum uric acid level, history of gout, obesity, pure systolic hypertension, heart rate at rest, ECG abnormalities, the "classical" major risk factors (hypercholesterolemia, hypertension, cigarette smoking), nutritional and physical activity indices, alcohol and coffee consumption, and such demographic variables as nativity, education and marital status.